Switching device for high frequency electrical energy



A 1959 J. B. TREVOR, JR 2,898,562

SWITCHING DEVICE FOR HIGH FREQUENCY ELECTRICAL ENERGY I Filed N09. 26, 1946 JOHN B. TREVOR JR.

United States Patent SWITCHING DEVICE FOR HIGH FREQUENCY ELECTRICAL ENERGY John B. Trevor, Jr., Brighton, N.Y.

Application November 26,1946, Serial No. 712,331

2 Claims. (Cl. 33398) (Granted under Title 35, U.S. Code (1952), see. 266) This invention relates to electrical energy switching devices and more particularly to switching devices of a type suitable for controlling the transmission of highfrequency electrical energy through waveguide systems.

In numerous applications of electrical energy transmission systems of the waveguide type it is desirable to effect switching so that the energy flow may be controlled. Certain applications further require high speed operation with a clean transition between the conductive and the non-conductive states. Switching devices for waveguide systems have been available in the past, however these prior systems suffer from numerous difiiculties such as undue complexity or serious limitation of the speed of operation.

Accordingly it is an object of the present invention to provide a switching device of simple structure for controlling the flow of electrical energy through a waveguide type transmission system.

Another object of the present invention is to provide a switching device of simple construction for high speed operation to control the flow of electrical energy through a waveguide type transmission system.

Other and further objects and features of the present invention will become apparent upon a careful consideration of the accompanying description and drawings.

Fig. l is a partly cut-away view of a waveguide transmission line system embodying the principles of the present invention.

Fig. 2 is an end View of the typical waveguide system showing in more detail the switching mechanism employed therein.

In accordance with the fundamental concepts of the present invention an electrical energy switching device for a waveguide type system is provided in which a movable member may be inserted or varied in position in the waveguide to vary the propagational characteristics thereof. One specific characteristic which may thus be varied is the cut-off frequency to permit or prevent transmission of energy of a selected frequency or frequency band.

With particular reference to Fig. l a waveguide switching device is shown embodying the features of the present invention. A section of waveguide which is cut-away at both ends is shown. The typical waveguide chosen for illustration is of the rectangular type for energy transfer in the simple modes in which the cut-off frequency is primarily dependent upon the spacing between the narrow bounding walls 11, 12. A Waveguide having close spacing between walls 11 and 12 will have a higher natural cut-off frequency for the simpler modes than one having wide spacing between the walls 11, 12.

Placed within the guide and parallel to the walls 11, 12 is a pair of flat rectangular plates 13, 14 shown through the cut-away portion of the guide 10. Plates 13 and 14 are parallel to one another and serve to constrict the width of the waveguide so that the cut-off frequency may be varied. In this connection it is desirable in most cases that the plates 13 and 14 establish good elec- ICE trical contact with the Walls 15 and 16. A driver device 17 is linked with plate 14 by means of bar 18. Device 17 is held in fixed position relative to the guide 10 by support members 19, 20. Longitudinal motion of the bar 18 produced by the driver 17 results in the motion of plate 14 toward or away from the plate 13. Since this space variation will produce a variation in the cut-off frequency of the waveguide, switching action can result provided the spacing adjustment is such that with minimum spacing between plates. 13, 14 the waveguide is operating below the cut-off frequency and with maximum spacing of plates 13, 14 the waveguide is capable of operating above the cut-off frequency. The range of operating frequency may be controlled by varying the amplitude of the motion of plate 14 at the driver 17. Another method of adjustment of this range is by a position variation of plate 13 by a positioning knob 21 shown in Fig. 2.

Where high speed switching action. is required the driving mechanism i7 may be actuated by a suitable high speed operating device such as an electrical relay or magnetic driver.

An end view of the waveguide structure is shown in Fig. 2. In addition to the correspondingly numbered parts of Fig. 1, rod 18 is supported at the side of waveguide 10 by a sleeve 22. Plate 13 is supported by rod 23 which is in turn held by the sleeve 24 placed in the side member 11. As previously mentioned, the positioning knob 21 may be employed to adjust plate 13.

From the foregoing discussion it is apparent that considerable modification of the features of the present invention is possible and while the device herein described and the form of apparatus for the operation thereof constitutes a preferred embodiment of the present invention it is to be understood that the invention is not limited to his precise device and form of apparatus and that changes may be made therein without departing from the scope of the invention which is defined in the appended claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

1. A high frequency switching device operable to instantaneously transmit or cut off the electrical energy flowing through a Waveguide by varying the effective width of said waveguide, comprising a rectangular waveguide, a movable plate located within and substantially parallel to one of the Walls of said waveguide, and rapid acting means connected to said plate for alternately varying the plate between two positions, in one position the effective width of said waveguide is reduced to a point where the cut off frequency of said waveguide is greater than the frequency of said electrical energy and in the other position the effective width of said waveguide is increased to a point where the cut oif frequency is equal to or less than the frequency of said electrical energy.

2. A high frequency switching device as defined in claim 1, wherein a second movable plate is mounted within said waveguide opposite the first mentioned moveable plate and manually operated positioning means connected to said second plate whereby the limits of waveguide cut-off frequency can be altered.

References Cited in the file of this patent UNITED STATES PATENTS 2,423,396 Linder July 1, 1947 2,433,368 Johnson Dec. 30, 1947 2,474,688 Pease June 28, 1949 2,505,557 Lyman Apr. 25, 1950 2,602,893 Ratiif July 8, 1952 

